I finally got around to watching it myself with my wife and son. I found it really gripping and watchable, and could tell there had been a special effort to make the science plausible.

The biggest hole in the science that I could see were the fierce Martian storms, the first of which causes the Mars mission to be aborted with the (apparent) loss of one of its members. On this forum few years ago, JamesG argued that because the Martian atmosphere is so very, very thin (approx 1/100 of that on Earth) fierce storms are actually impossible - mild breezes would be as bad as it ever gets, and the dust only gets stirred up by them because gravity there is so weak.

We could (and did) argue about the degree of this, but it is surely the case that with an atmospheric pressure only 1/100 of Earth's, it is very hard to imagine the destructive, savage storms which form vital parts of the plot at two different points in the movie.